In some wireless communication systems, for example, cellular communication systems, a power control module may be used to control the power of a transmitted signal. For example, in a Wideband Code Division Multiple Access (WCDMA) cellular system, a mobile station (MS) may be able to transmit radio frequency (RF) signals with a wide power range, for example, a 75 dB. Thus, a power control module at the MS may control the power of the transmitted signal over the power range of 75 dB with an accuracy of, for example, ±0.5 dB for a 1 dB power step.
In order to meet the requirements of WCDMA standards, calibration of the MS transmitter may be needed. The calibration of the MS transmitter may be performed at the MS manufacturer's production line and may consume large resources. Furthermore, many calibration steps, e.g., 75 steps in the example above, may be required to calibrate the MS transmitter, and the calibration parameters of the calibration steps may be stored at the MS memory.
Thus, there is a need for improved transmitter calibration, which mitigates the above-described disadvantages.
It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements.